True bipolar or extended bipolar left ventricular pacing is associated with better survival in cardiac resynchronization therapy patients.

BACKGROUND: Limited studies are available on the clinical significance of left ventricular (LV) lead polarity in patients undergoing cardiac resynchronization therapy (CRT), with a recent study suggesting better outcomes with LV true bipolar pacing. OBJECTIVE: We aimed to determine whether true bipolar LV pacing is associated with reduced mortality in a large, real-life CRT cohort, followed by remote monitoring. METHODS: We analyzed de-identified device data from CRT patients followed by the Boston Scientific LATITUDE remote monitoring database system. Patients with LV bipolar leads paced between the LV ring and LV tip were identified as true bipolar and those with LV bipolar leads paced between LV tip or LV ring and right ventricular (RV) coil were identified as extended bipolar. Patients with unipolar leads were identified as unipolar. RESULTS: Of the 59 046 patients included in the study, 2927 had unipolar pacing, 34 390 had extended bipolar pacing, and 21 729 had true bipolar pacing. LV true bipolar pacing was associated with a significant 30% lower risk of all-cause mortality as compared to unipolar pacing (hazards ratio [HR] = 0.70, 95% CI: 0.62-0.79, P < .001), after adjustment for age, gender, LV lead impedance, LV pacing threshold, and BIV pacing percentage <95%. Extended bipolar LV pacing was also associated with 24% lower risk of all-cause mortality when compared to unipolar LV pacing (HR = 0.76, 95% CI: 0.68-0.85; P < .001). However, there were no differences in outcomes between true bipolar and extended bipolar LV pacing (HR = 0.97, 95% CI: 0.93-1.01; P = .198). CONCLUSION: True bipolar or extended bipolar LV pacing is associated with a lower risk of mortality in CRT patients as compared to unipolar LV pacing.

Long-term clinical outcomes from real-world experience of left atrial appendage exclusion with LARIAT device.

BACKGROUND: Left atrial appendage closure (LAAC) with LARIAT has emerged as one of the alternatives to oral anticoagulation (OAC) in patients with nonvalvular atrial fibrillation (AF). Our aim was to study long-term outcomes in patients undergoing LARIAT procedure. METHODS: We analyzed patients screened for LARIAT device in four centers between December 2009 and June 2012. Out of these, patients who didn't undergo LAAC with the LARIAT device due to unfavorable LAA morphology and other preprocedural contraindications were included in control group. We analyzed thromboembolism, bleeding events, and mortality between LAA and control group. RESULTS: About 153 patients were screened. Out of these, 108 (70.6%) patients underwent LARIAT placement (LAA arm) and 45 (29.4%) excluded patients were included in control arm. There were no differences in CHADS2 and CHA2 DS2 -VASc score. Mean HAS-BLED score was significantly higher in the LARIAT group (3.5 ± 1.06 vs 3.09 ± 1.22, P = .04). Mean follow-up time (in years) was 6.56 ± 0.84 in LAA and 6.5 ± 1.26 in control arm. During follow-up period, the LARIAT group was associated with significantly less thromboembolic events (1.9% vs 24%, P < .001), bleeding events (9.2% vs 24.4%, P = .03), and mortality (5.6% vs 20%, P = .01) as compared with the control group. CONCLUSIONS: Long-term data from routine clinical practice from our study suggests that LAA exclusion with LARIAT device is an effective treatment in management of nonvalvular AF patients with high risk of stroke, bleeding, and mortality. Further randomized trials, such as aMAZE, will provide more insight in this expanding field.

Comparative safety of periablation anticoagulation strategies for atrial fibrillation: data from a large multicenter study.

BACKGROUND: There are a variety of periprocedural anticoagulation strategies for atrial fibrillation (AF) ablation, including the use of dabigatran. It is unclear which strategy is superior. OBJECTIVE: To compare the safety and efficacy of anticoagulation with uninterrupted warfarin, dabigatran, and warfarin with heparin bridging in patients undergoing ablation of AF at four experienced centers. METHODS AND RESULTS: In this retrospective analysis, 882 patients (mean age: 61 ± 11 years) underwent ablation of AF using uninterrupted warfarin (n = 276), dabigatran (n = 374), or warfarin with heparin bridging (n = 232) for periprocedural anticoagulation. The rate of total complications was 23/276 (8.3%) in the uninterrupted warfarin group, 30/374 (8.0%) in the dabigatran group, and 29/232 (12.5%) in the bridged group (P = 0.15). Major complications were more frequent in the uninterrupted warfarin group 12/276 (4.3%) compared with 3/374 (0.8%) in dabigatran and 6/232 (2.6%) in the bridged group (P = 0.01). The most common major complication was the need for transfusion or occurrence of major bleeding. Minor complications did not differ among the three groups. On multivariate analysis, female gender (odds ratio [OR] 1.93, confidence interval [CI] 1.16-3.19, P = 0.011), bridging heparin (OR 2.13, CI 1.100-3.941, P = 0.016), use of triple antithrombotic therapy (OR 1.77, CI 1.05-2.98, P = 0.033), and prior myocardial infarction (OR 2.40, CI 1.01-5.67, P = 0.046) independently predicted total complications. CONCLUSIONS: When comparing the use of uninterrupted warfarin, dabigatran, and warfarin with heparin bridging in patients undergoing catheter ablation of AF, dabigatran was not associated with increased risk, major complications were more common in the uninterrupted warfarin group, and after adjustment, warfarin with bridging increased total complications.

Defining the blanking period, using continuous ECG monitoring, after cryoballoon pulmonary vein isolation.

BACKGROUND: Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. A blanking period (BP) of 3 months is used in clinical trials and practice. However, the optimal BP duration after PVI remains undefined. OBJECTIVE: The aim of this study was to objectively define, using continuous monitoring by an implantable loop recorder, the optimal BP duration after cryoballoon PVI. METHODS: We enrolled consecutive patients who had cryoballoon PVI and an implantable loop recorder. We determined the time of the last confirmed episode of AF within the blanking period. This was then correlated with AF recurrence in the first year after ablation. RESULTS: There were 210 patients (66 ± 9 years; 138 [66%] male; 116 [55%] paroxysmal AF; CHA2DS2-VASc score, 2.5 ± 1.6). We defined 4 distinct groups based on the last AF episode within the BP: no AF days 0-90 (n = 96 [46%]) and last AF 0-30 days (n = 46 [22%]), 31-60 days (n = 18 [9%]), and 61-90 days (n = 50 [24%]). After the 3-month BP, 101 (48%) patients had AF recurrence at 160 ± 86 days. Compared with patients with no AF in the BP, those with recurrent AF and AF burden >0% 30 days after ablation had a significantly greater AF recurrence during long-term follow-up (P = .001). CONCLUSION: Our data show that the approximately one-third of patients in whom AF occurs and who have a burden of >0% after the first month that follows PVI are at significantly higher risk of long-term recurrent AF. We therefore suggest that the blanking period be limited to a month after cryoballoon PVI.

Sex-Related Differences in Ventricular Tachyarrhythmia Events in Patients With Implantable Cardioverter-Defibrillator and Prior Ventricular Tachyarrhythmias.

BACKGROUND: Data on the risk of ventricular tachycardia (VT), ventricular fibrillation (VF), and death by sex in patients with prior VT/VF are limited. OBJECTIVES: This study aimed to assess sex-related differences in implantable cardioverter-defibrillator (ICD)-treated VT/VF events and death in patients implanted for secondary prevention or primary prevention ICD indications who experienced VT/VF before enrollment in the RAID (Ranolazine Implantable Cardioverter-Defibrillator) trial. METHODS: Sex-related differences in the first and recurrent VT/VF requiring antitachycardia pacing or ICD shock and death were evaluated in 714 patients. RESULTS: There were 124 women (17%) and 590 men observed during a mean follow-up of 26.81 ± 14.52 months. Compared to men, women were at a significantly lower risk of VT/VF/death (HR: 0.67; P = 0.029), VT/VF (HR: 0.68; P = 0.049), VT/VF treated with antitachycardia pacing (HR: 0.59; P = 0.019), and VT/VF treated with ICD shock (HR: 0.54; P = 0.035). The risk of recurrent VT/VF was also significantly lower in women (HR: 0.35; P < 0.001). HR for death was similar to the other endpoints (HR: 0.61; P = 0.162). In comparison to men, women presented with faster VT rates (196 ± 32 beats/min vs 177 ± 30 beats/min, respectively; P = 0.002), and faster shock-requiring VT/VF rates (258 ± 56 beats/min vs 227 ± 57 beats/min, respectively; P = 0.30). There was a significant interaction for the risk of VT/VF by race (P = 0.013) with White women having significantly lower risk than White men (HR: 0.36; P < 0.001), whereas Black women had a similar risk to Black men (HR: 1.06; P = 0.851). CONCLUSIONS: Women with a history of prior VT/VF experienced a lower risk recurrent VT/VF requiring ICD therapy when compared to men. Black Women had a risk similar to men, whereas the lower risk for VT/VF in women was observed primarily in White women. (Ranolazine Implantable Cardioverter-Defibrillator Trial; NCT01215253).

Right ventricular dysfunction is a strong predictor of developing atrial fibrillation in acutely decompensated heart failure patients, ACAP-HF data analysis.

BACKGROUND: Heart failure and atrial fibrillation (AFib) are the twin epidemics of modern cardiovascular disease. The incidence of new-onset AFib in acute decompensated heart failure (ADHF) patients is difficult to predict and the short- and long-term outcomes of AFib in a cohort of patients admitted with ADHF are unknown. METHODS AND RESULTS: A total of 904 patients admitted with ADHF were studied. Incidence of AFib on admission was recorded and a multivariate analysis was performed using echocardiographic parameters to specify the predictors of AFib incidence in this cohort. In 904 ADHF patients (57% male, mean age 69 ± 14 years), 81% had history of hypertension, 40% were diabetics, and 51% were smokers. A total of 63% of the patients had known heart failure (HF) with mean ejection fraction of 34% ± 21%, and 33% of the patients had ischemic cardiomyopathy as the etiology of HF. Echocardiographic parameters were: left atrial (LA) diameter 4.5 ± 0.8 cm, left ventricular end-systolic 4.1 ± 1.3 cm, left ventricular end-diastolic 5.3 ± 1.1 cm. Right ventricular dysfunction (RVD) was present in 34% of the patients. A total of 191 (21%) patients subsequently developed AFib with two thirds of the cases occurring in patients with RVD. Using a univariate analysis, older age (OR 1.02; P < .0001), history of HF (OR 2.93; P < .0001), LA dilation (OR 1.58; P < .0001), the presence of left ventricular hypertrophy (OR 3.01, P < .0001), and RVD (OR 4.93; P < .00001) were the strongest predictors for AFib. Controlling for LA size and left ventricular hypertrophy using a forward stepwise regression, RVD remained the strongest predictor (OR 4.45; P < .0001). Patients with RVD had more events (cardiac readmission and mortality) than those with normal RV (56% versus 38%; P < .00001), notably; all-cause mortality was 4.7%/year in the abnormal RV group versus 2.9%/year in the normal RV group; P < .05. RV function analyses by echocardiography further risk stratified these patients based on their rhythm categorizing those patients with abnormal RV and AFib as the ones with the worse prognosis. CONCLUSION: RV dysfunction is a strong predictor for developing AFib in acutely decompensated systolic failure patients. Patients with AFib and RVD have the worse outcome specially when is combined with LV dysfunction, therefore; evaluation of RV function may substantiate the difference in HF prognosis.

Computational method to predict esophageal temperature elevations during pulmonary vein isolation.

BACKGROUND: The esophagus is in close proximity to the posterior wall of the left atrium, which renders it susceptible to thermal injury during radiofrequency (RF) ablation procedures for atrial fibrillation (AF). Real-time assessment of esophageal position and temperature (T°) during pulmonary vein (PV) isolation has not been extensively explored. OBJECTIVE: To develop a protocol that allows estimation of the potential for, and avoidance of, esophageal heating. METHODS: In consecutive patients who underwent PV isolation, a thermal probe was used to monitor T° fluctuations in the esophagus during application of RF energy. The tip of the thermal probe was positioned at the level of the targeted PV and RF was discontinued for T° rise >0.5°C. The proximity of individual PVs to the esophagus was measured from the temperature probe tip to the closest posterior part of the Lasso catheter from review of biplane projections (left anterior oblique 60° and right anterior oblique 30°). These raw distances were entered into the Pythagorean theorem and the actual distance between the esophageal thermal probe and PV antrum was determined. RESULTS: The study cohort included 44 patients (60 ± 11 years, 61% male, 57% lone AF). The thermal probe in the esophagus was closer to the left-sided PVs (left common pulmonary vein: 20.9 ± 13 mm, left upper pulmonary vein: 20.5 ± 11 mm, left lower pulmonary vein: 23.4 ± 10 mm) than the right-sided ones (right common pulmonary vein: 31.0 ± 11 mm, right upper pulmonary vein: 41.9 ± 18 mm, right lower pulmonary vein: 34.5 ± 16 mm). A T° increase >0.5° C occurred during 116/1,495 (7.8%) deliveries. A T° rise was more likely during ablation of left-sided PVs than right-sided PVs (55% vs 10%, P < 0.0001) and when RF was delivered ≤ 24 mm from the esophagus (sensitivity 91%, specificity 81%, positive predictive value 75%, and negative predictive value 93%). CONCLUSION: A thermal probe placed in the esophagus provides real-time T° monitoring and anatomic localization. A T° rise is more likely during ablation of left PVs and during RF deliveries within 24 mm of the esophageal thermal probe.

Incidence, duration, pattern, and burden of de novo atrial arrhythmias detected by continuous ECG monitoring using an implantable loop recorder following ablation of the cavotricuspid isthmus.

Background: Following cavotricuspid isthmus (CTI) ablation, many patients with atrial flutter (AFL) are diagnosed with atrial fibrillation (AF). The incidence, duration, pattern, and burden of AF remain undefined. These may have implications for the management of these patients. Objective: To classify the incidence, duration, pattern, and burden of AF/AFL using an implantable loop recorder (ILR) after CTI ablation. Methods: We enrolled consecutive patients with CTI-dependent AFL, no known history of AF, and CHA2DS2-VASc ≥ 2. An ILR was implanted before or within 90 days of ablation. The time to first AF/AFL, pattern, duration, and burden of longest AF/AFL were determined. Five distinct AF/AFL cohorts were identified: no AF/AFL and those with recurrences of isolated, clustered, frequent, or persistent AF/AFL. Results: Fifty-two patients (81% male; 73 ± 9 years; CHA2DS2-VASc 3.7 ± 1.2) were followed for 784 (interquartile range [IQR] 263, 1150) days. AF/AFL occurred in 44 (85%) patients at 64 (IQR 8, 189) days post-CTI ablation and was paroxysmal in 31 (70%) patients (burden 0.6% [IQR 0.1, 4.8]). AF/AFL was isolated (n = 5, 11%), clustered (n =7, 16%), frequent (n =19, 43%), and persistent (n =13, 30%). The longest AF episode was <24 hours in 27 (61%) patients. Conclusion: Following CTI ablation in AFL patients, although AF/AFL occurs in most patients, the burden is low and episodes were <24 hours in the majority of patients. Additional studies are needed to determine whether long-term electrocardiographic monitoring can help guide management of patients undergoing CTI ablation.

Detection of atrial fibrillation using an implantable loop recorder following cryptogenic stroke: implications for post-stroke electrocardiographic monitoring.

PURPOSE: Approximately 10-40% of strokes are cryptogenic (CS). Long-term electrocardiographic (ECG) monitoring has been recommended in these patients to search for atrial fibrillation (AF). An unresolved issue is whether ambulatory ECG (AECG) monitoring should be performed first, followed by an implantable loop recorder (ILR) if AECG monitoring is non-diagnostic, or whether long-term ECG monitoring should be initiated using ILRs from the onset. The purpose of this study was to assess, using an ILR, AF incidence in the first month after CS. METHODS: We enrolled consecutive CS patients referred for an ILR. All patients were monitored via in-hospital continuous telemetry from admission until the ILR (Medtronic [Minneapolis, MN] LINQ™) was implanted. The duration and overall burden of all AF episodes ≥ 2 min was determined. RESULTS: The cohort included 343 patients (68 ± 11 years, CHA2DS2-VASc 3.5 ± 1.7). The time between stroke and ILR was 3.7 ± 1.5 days. During the first 30 days, only 18 (5%) patients had AF. All episodes were paroxysmal, lasting from 2 min to 67 h and 24 min. The median AF burden was 0.85% (IQR 0.52, 10.75). During 1 year of follow-up, 67 (21%) patients had AF. CONCLUSION: The likelihood of AF detection by an ILR in the first month post-CS is low. Thus, the diagnostic yield of 30 days of AECG monitoring is likely to be limited. These data suggest a rationale for proceeding directly to ILR implantation prior to hospital discharge in CS patients, as many have AF detected during longer follow-up.

Incidence and Predictors of Very Late Recurrence of Atrial Fibrillation Following Cryoballoon Pulmonary Vein Isolation.

BACKGROUND: A very late recurrence (VLR) of atrial fibrillation (AF) is considered present when the first recurrence of AF occurs ≥12 months following ablation. Prior studies characterizing VLR have not used an implantable loop recorder for ECG monitoring. Thus, it is unknown whether VLR truly occurs or whether these patients have simply had unrecognized AF. Our objective was to assess the incidence and predictors of VLR in patients who underwent cryoballoon pulmonary vein isolation alone, had an implantable loop recorder, and were confirmed AF free for at least 1 year. METHODS: We enrolled consecutive patients with paroxysmal or persistent AF who underwent cryoballoon pulmonary vein isolation and had an implantable loop recorder implanted <3 months post-ablation. Patients free of AF 1 year post-ablation were followed prospectively for recurrent AF. All AF episodes were adjudicated. RESULTS: We included 188 patients (66±10 years; 116 [62%] men; 102 [54%] paroxysmal AF; CHA2DS2-VASc, 2.6±1.7). After 1 year post-pulmonary vein isolation, 93 (49%) patients remained AF free. During subsequent follow-up, 30 (32%) patients had VLR of AF. The only independent risk factor for VLR was an elevated CHA2DS2-VASc score (hazard ratio, 1.317 [95% CI, 1.033-1.6979]; P=0.026). Patients with CHA2DS2-VASc score ≥4 represented a quarter of the population and were at the highest risk. CONCLUSIONS: Our data using implantable loop recorders for continuous ECG monitoring post-AF ablation show that VLR occurs in a third of patients after an apparently successful cryoballoon pulmonary vein isolation procedure. Additional strategies are needed to ensure long-term freedom from AF recurrences in these high-risk patients.

Venous Vascular Closure System Versus Manual Compression Following Multiple Access Electrophysiology Procedures: The AMBULATE Trial.

OBJECTIVES: This study compared the efficacy and safety of the VASCADE MVP Venous Vascular Closure System (VVCS) device (Cardiva Medical, Santa Clara, California) to manual compression (MC) for closing multiple access sites after catheter-based electrophysiology procedures. BACKGROUND: The VASCADE MVP VVCS is designed to provide earlier ambulatory hemostasis than MC after catheter-based procedures. METHODS: The AMBULATE (A Randomized, Multi-center Trial to Compare Cardiva Mid-Bore [VASCADE MVP] VVCS to Manual Compression in Closure of Multiple Femoral Venous Access Sites in 6 - 12 Fr Sheath Sizes) trial was a multicenter, randomized trial of device closure versus MC in patients who underwent ablation. Outcomes included time to ambulation (TTA), total post-procedure time (TPPT), time to discharge eligibility (TTDe), time to hemostasis (TTH), 30-day major and minor complications, pain medication usage, and patient-reported outcomes. RESULTS: A total of 204 patients at 13 sites were randomized to the device arm (n = 100; 369 access sites) or the MC arm (n = 104; 382 access sites). Baseline characteristics were similar between groups. Mean TTA, TPPT, TTDe, and TTH were substantially lower in the device arm (respective decreases of 54%, 54%, 52%, and 55%; all p < 0.0001). Opioid use was reduced by 58% (p = 0.001). There were no major access site complications. Incidence of minor complications was 1.0% for the device arm and 2.4% for the MC arm (p = 0.45). Patient satisfaction scores with duration of and comfort during bedrest were 63% and 36% higher in device group (both p < 0.0001). Satisfaction with bedrest pain was 25% higher (p = 0.001) for the device overall, and 40% higher (p = 0.002) for patients with a previous ablation. CONCLUSIONS: Use of the closure device for multiple access ablation procedures resulted in significant reductions in TTA, TPPT, TTH, TTDe, and opioid use, with increased patient satisfaction and no increase in complications. (A Randomized, Multi-center Trial to Compare Cardiva Mid-Bore VVCS to Manual Compression in Closure of Multiple Femoral Venous Access Sites in 6 - 12 Fr Sheath Sizes [AMBULATE]; NCT03193021).

LARIAT Trial Updates.

The thrombus formed within the LAA is responsible for the vast (about 90%) majority of strokes. Anticoagulation, although effective therapy for stroke prevention is not feasible in a significant minority of patients due to various reasons. Two percutaenous LAA exclusion techniques have been developed in an effort to decrease risk for stroke: endocardial closure/plugging of the LAA (Watchman, Amplatzer devices) and epicardial LAA ligation (LARIAT). The aim of this study is to review the trial data to date for the LARIAT device. The LARIAT suture has been used in more than 4500 patients with high success of LAA complete closure (92-100%), mostly in the patients unable to take anticoagulation and in a small minority as antiarrhythmic option. The LARIAT technique has evolved with a change in pericardial access method that resulted in dramatic improvement of safety. LAA closure performance with LARIAT system seems to be similar to Watchman device, with small leaks during follow-up in 6-24% of the cases, which do not to correlate with thrombo-embolic events. LAA has been proven to play an important triggering role in patients with persistent atrial fibrillation. Small studies had shown that LAA ligation with LARIAT could terminate persistent atrial fibrillation and possible improve ablation success. Ongoing aMAZE randomized trial is studying if LAA ligaiton using LARIAT suture leads to improved atrial fibrillation ablation success. Available data suggests that LAA closure using LARIAT epicardial suture is a good alternative for stroke risk reduction in patients who are unable to be on anticoagulation therapy. LARIAT system might improve success of AF ablation for patients with persistent and long persistent AF, pending the results of the ongoing aMAZE trial.

Implantable Loop Recorders for Cryptogenic Stroke (Plus Real-World Atrial Fibrillation Detection Rate with Implantable Loop Recorders).

Cryptogenic stroke (CS) represents 10%-40% of ischemic strokes and is associated with significant morbidity and mortality and high risk of recurrence. Undetected atrial fibrillation is an important consideration in these patients. Tools for electrocardiographic monitoring range from 12-lead electrocardiogram to implantable loop recorders (ILRs). ILRs have become an important tool for long-term electrocardiogram monitoring in CS patients. Advancements in ILR technology are needed to ensure more robust connectivity and to help triage incoming data. An unresolved issue is what duration of AF indicates that the CS patient is at high risk for recurrent stroke and thus would benefit from initiation of anticoagulation.

The Efficacy of His Bundle Pacing: Lessons Learned From Implementation for the First Time at an Experienced Electrophysiology Center.

OBJECTIVES: This study sought to evaluate the clinical and procedural characteristics impacting outcomes during implementation of a His bundle pacing (HBP) program in a real-world setting. BACKGROUND: Right ventricular pacing is associated with an elevated risk of heart failure, but device reprogramming and upgrades have significant challenges. HBP has emerged as an alternative and is reported to be highly successful in the hands of highly experienced centers. METHODS: All patients referred for permanent pacemaker implantation at the Valley Hospital (Ridgewood, New Jersey) between October 2015 and October 2017 were evaluated; a subset of 24% was selected for HBP. RESULTS: Permanent HBP was feasible with an acute implant success rate of 75%. HBP in the presence of bundle branch block (64% vs. 85%; p = 0.05) or complete heart block (56% vs. 83%; p = 0.03) was significantly less successful. The pattern of atrioventricular block in combination with bundle branch block (BBB) further affects outcomes. HBP is highly successful across the spectrum of atrioventricular block pattern severity in the absence of BBB. In the presence of BBB, Mobitz II AV block and complete heart block significantly attenuated HBP success compared with Mobitz I atrioventricular block (62% vs. 100%; p = 0.02). A rising threshold was observed in 30%, and 8% required lead intervention. CONCLUSIONS: HBP was feasible and readily learned with a high implant success in the hands of experienced electrophysiologists without prior exposure to the technique. BBB and atrioventricular block pattern appears to affect success. The technique is limited by a high rate of rising thresholds and lead intervention. These data have important implications for patient selection.

Increased healthcare utilization associated with complete atrioventricular block in pacemaker patients.

PURPOSE: The purpose of the current study is to characterize and quantify the impact of complete atrioventricular block (cAVB) on heart failure hospitalization (HFH) and healthcare utilization in pacemaker (PM) patients. METHODS: Patients ≥ 18 years implanted with a dual-chamber PM from April 2008 to March 2014 were selected from the MarketScan® Commercial and Medicare Supplemental claims databases. Patients with ≤ 1-year continuous MarketScan enrollment prior to and post-implant, and those with prior HF diagnosis were excluded. Patients were dichotomized into those with cAVB, defined as a 3rd degree AVB diagnosis or AV node ablation in the year prior to PM implant, versus those without any AVB (noAVB). Post-implant HFH and associated costs were compared based on inpatient claims. RESULTS: The study cohort included 21,202 patients, of which 14,208 had no AVB and 6994 had cAVB, followed for 2.39 and 2.27 years, respectively. Patients with cAVB were associated with a significantly increased risk of cumulative HFH (HR 1.59 [95% CI 1.35-1.86] p < 0.001) and significantly higher costs ($636 [609-697] vs $369 [353-405] per pt-year, p < 0.001) compared to those with no AVB. CONCLUSIONS: Among dual-chamber PM patients without prior HF, cAVB is associated with a significantly increased risk of HFH and greater HF-related healthcare utilization. Identifying patients at high risk for HF in the setting of RV pacing, and potentially earlier use of biventricular or selective conduction system pacing, may reduce HF-related healthcare utilization.

Focal impulse and rotor modulation: Acute procedural observations and extended clinical follow-up.

BACKGROUND: Focal impulse and rotor modulation (FIRM) was based on the premise that atrial fibrillation (AF) is sustained by rotors that are sufficiently stable to be eliminated by targeted ablation. Early experience reported high success as compared to conventional strategies. OBJECTIVE: The purpose of this study was to report on a single-center experience with extended follow-up by using FIRM in a variety of patients with AF. METHODS: All FIRM-guided ablation procedures were included. During spontaneous or induced AF, FIRM software constructed phase maps to identify putative AF sources, then targeted for radiofrequency ablation, with adjunctive pulmonary vein isolation (PVI), if needed. All mapped rotors and/or sources were eliminated on the basis of repeated FIRM mapping. RESULTS: Of 47 patients, sustained AF was not present or induced in 4 patients who did not undergo FIRM ablation. Of the remaining 43 patients, prior AF was paroxysmal in 9 (21%) and 72% had a median of 1 prior PVI. Spontaneous AF (n = 22, 52%) and induced AF (n = 21, 49%) were mapped, and all patients had rotors identified (1.8 ± 0.8 per patient; 70% in the left atrium). AF termination occurred in 2 patients (5%) and none organized to atrial tachycardia. Touch-up redo PVI was also performed in 31 patients (72%). At 16.0 ± 10.7 months (range 1-34 months), only 9 patients (21%) were free of recurrent AF; and only 5 patients (12%) were free of AF and off antiarrhythmic drugs. CONCLUSION: Long-term clinical results after FIRM ablation in this diverse challenging cohort showed poor efficacy. Randomized clinical trials are needed to evaluate the efficacy and clinical utility of the FIRM ablation approach for treating AF.